There’s been an outbreak of COVID linked to a spin studio in Ontario. It has the markers to look like a superspreader event with at least 50 cases tied to the studio. The studio was following Provincial protocols and has been working with the local public health authorities to investigate the cause, and steps moving forward.
Superspreader events are those in which a single person is responsible for the infection of a large number of people—typically greater than 50, though there is no formal definition. One such event is ongoing in a spinning studio in Hamilton, Ontario. As of this writing, CBC reports that 72 COVID-19 cases have been linked to the studio: 45 members, two staff, and 25 secondary contacts. Cases could grow as exposure may reach an additional 100 members and more secondary contacts. Exposure occurred over a several day period between September 28 – October 5, and it is reported “patient zero” exhibited no symptoms.
Where Do We Go from Here?
The studio has closed for 14 days and is working with health authorities to investigate the cause and determine additional protocols.
COVID-19 is still a novel disease, and there is a lot we do yet fully understand. Several studies have demonstrated that SARS-CoV-2 forms aerosols that can linger in the air, though there is no consensus on how much this contributes to transmission. Scientists also do not know what proportion of exhaled droplets from speaking, breathing, or singing evaporate to form aerosols, nor what dose of infected particles would result in a COVID-19 infection.
The club in Hamilton was following local safety protocols, some of which include:
- Extensive and frequent cleaning using hospital-grade solution, and sanitizing wipes for members to use on their equipment.
- Temperature checks and screening prior to class attendance.
- Mask policy requiring face coverings upon entering and leaving the studio and walking to one’s bike. A person could only remove their mask once on their bike and ready for class.
- Floor markings and arrival and departure policies to facilitate social distancing.
- Limited capacity operation—studios were at 50% capacity with 21 bikes instead of 43.
It is unclear from the club’s Return to Ride safety protocols whether or not the facility had implemented any enhanced safety measures with regard to their HVAC system.
Despite these measures, an outbreak occurred, highlighting just how challenging these superspreading events can be to predict and prevent.
What We Know about COVID-19 Transmission
Early in the pandemic, superspreader events were a primary driver of COVID-19 transmission, with evidence from Hong Kong, Israel, and London suggesting between 1-19% of people were responsible for 80% of COVID-19 transmission. More recently, small social gatherings seem to be driving spread.
Superspreader events are uncommon, unpredictable, and can happen in any venue, from a meeting of Biotech leaders to the White House Rose Garden.
Events with large spread are facilitated by a couple of factors occurring simultaneously: a highly infectious person coming into contact with a large number of people during the period at which they are most contagious. According to one non-peer-reviewed preprint, this period occurs for a half-day to one day period two to six days after infection.
Asymptomatic and pre-symptomatic transmission of disease also play a key role. That infectivity starts 5-6 days prior to symptom onset and peaks as symptoms emerge means highly infectious people are often most contagious before they even realize they are sick.
Health clubs have been open around the world for months, and have not seen a large outbreak in traditional fitness centers. Before this event, the Hamilton studio had also been open for several months without any cases. Evidence from several states’ contact tracing, a CDC case control study, and industry check in data point to the fact that health clubs are, for the most part, not a primary driver of COVID-19 spread.
Key Measures to Help Prevent Airborne Spread of COVID-19
Despite the challenges of predicting superspreading events like this one, there are still measures businesses can take to reduce the risk of COVID-19 transmission, especially in light of continued evidence suggesting airborne spread. According to the WHO, “A well-maintained and operated [HVAC] system can reduce the spread of COVID-19 in indoor spaces by increasing the rate of air change, reducing recirculation of air and increasing the use of outdoor air.”
Lindsey C. Marr, Professor of Civil and Environmental Engineering at Virginia Tech University, outlined four key strategies to reduce aerosol spread of SARS-CoV-2 indoors in her Plenary Session on The Role of Aerosols in the Transmission of COVID-19 at the 38th Annual American Association of Aerosol Researchers (AAAR) conference.
1. Wearing a mask to help prevent the spread of COVID-19 from person to person. IHRSA details the Safety and Efficacy of Exercising in a Mask and highlights some popular workout friendly masks (though health authorities do not advise wearing a mask during high intensity exercise).
2. Maintaining social distancing—exceeding 6 feet or 2 meters depending on the activity—to remove direct contact transmission by limiting contact with respiratory plumes and droplets.
3. Ventilation and filtration to dilute virus aerosols, maintaining lower density and concentrations of any present virus in the air.
4. Hygiene, including handwashing, which removes the chance for direct and indirect transmission. Cleaning floors and surfaces is also important because settled viral particles can re-aerosolize, putting them back into the air circulation.
The scientific community and the industry continues to research and understand factors that facilitate widespread COVID-19 transmission—such as airborne particles. As they have since the start of the pandemic, the fitness industry will continue to evolve and adapt to create the safest possible environment for their members and communities to be physically active.
Alexandra Black Larcom, MPH, RD, LDN, is the Senior Manager of Health Promotion & Health Policy for IHRSA. She spends her days working on resources and projects that help IHRSA clubs offer effective health programs in their communities, and convincing lawmakers that policies promoting exercise are an excellent idea. Outside the office you’ll most likely find Alex at the gym, running on the Charles River, or, in the fall, by a TV cheering on the Florida Gators.
The International Health, Racquet & Sportsclub Association (IHRSA) is a global community of health and fitness professionals committed to building their businesses and improving their communities’ health and well-being. The mission of IHRSA is to grow, protect, and promote the health and fitness industry, and to provide its members with the benefits that will help them be more successful. IHRSA and its members (health clubs and fitness facilities, gyms, spas, sports clubs, and industry suppliers) are dedicated to make the world healthier through regular exercise. For more information visit www.ihrsa.org.